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/* clock_gettime -- Get current time from a POSIX clockid_t. Linux version.
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Copyright (C) 2003, 2004 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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#include "kernel-posix-cpu-timers.h"
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#include <bits/kernel-features.h>
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#define SYSCALL_GETTIME \
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retval = INLINE_SYSCALL (clock_gettime, 2, clock_id, tp); \
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#ifdef __ASSUME_POSIX_TIMERS
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/* This means the REALTIME and MONOTONIC clock are definitely
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supported in the kernel. */
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# define SYSDEP_GETTIME \
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SYSDEP_GETTIME_CPUTIME \
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case CLOCK_REALTIME: \
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case CLOCK_MONOTONIC: \
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# define __libc_missing_posix_timers 0
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#elif defined __NR_clock_gettime
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/* Is the syscall known to exist? */
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int __libc_missing_posix_timers attribute_hidden;
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maybe_syscall_gettime (clockid_t clock_id, struct timespec *tp)
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if (!__libc_missing_posix_timers)
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INTERNAL_SYSCALL_DECL (err);
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int r = INTERNAL_SYSCALL (clock_gettime, err, 2, clock_id, tp);
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if (!INTERNAL_SYSCALL_ERROR_P (r, err))
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e = INTERNAL_SYSCALL_ERRNO (r, err);
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__libc_missing_posix_timers = 1;
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/* The REALTIME and MONOTONIC clock might be available. Try the
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# define SYSDEP_GETTIME \
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SYSDEP_GETTIME_CPUTIME \
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case CLOCK_REALTIME: \
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case CLOCK_MONOTONIC: \
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retval = maybe_syscall_gettime (clock_id, tp); \
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/* Fallback code. */ \
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if (retval == EINVAL && clock_id == CLOCK_REALTIME) \
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retval = realtime_gettime (tp); \
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__set_errno (retval); \
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#ifdef __NR_clock_gettime
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/* We handled the REALTIME clock here. */
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# define HANDLED_REALTIME 1
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# define HANDLED_CPUTIME 1
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# if __ASSUME_POSIX_CPU_TIMERS > 0
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# define SYSDEP_GETTIME_CPU SYSCALL_GETTIME
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# define SYSDEP_GETTIME_CPUTIME /* Default catches them too. */
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int __libc_missing_posix_cpu_timers attribute_hidden;
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maybe_syscall_gettime_cpu (clockid_t clock_id, struct timespec *tp)
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if (!__libc_missing_posix_cpu_timers)
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INTERNAL_SYSCALL_DECL (err);
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int r = INTERNAL_SYSCALL (clock_gettime, err, 2, clock_id, tp);
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if (!INTERNAL_SYSCALL_ERROR_P (r, err))
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e = INTERNAL_SYSCALL_ERRNO (r, err);
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# ifndef __ASSUME_POSIX_TIMERS
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__libc_missing_posix_timers = 1;
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__libc_missing_posix_cpu_timers = 1;
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/* Check whether the kernel supports CPU clocks at all.
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If not, record it for the future. */
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r = INTERNAL_SYSCALL (clock_getres, err, 2,
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MAKE_PROCESS_CPUCLOCK (0, CPUCLOCK_SCHED),
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if (INTERNAL_SYSCALL_ERROR_P (r, err))
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__libc_missing_posix_cpu_timers = 1;
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# define SYSDEP_GETTIME_CPU \
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retval = maybe_syscall_gettime_cpu (clock_id, tp); \
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if (retval != EINVAL || !__libc_missing_posix_cpu_timers) \
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__set_errno (retval); \
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retval = -1 /* Otherwise continue on to the HP_TIMING version. */;
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maybe_syscall_gettime_cputime (clockid_t clock_id, struct timespec *tp)
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return maybe_syscall_gettime_cpu
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(clock_id == CLOCK_THREAD_CPUTIME_ID
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? MAKE_THREAD_CPUCLOCK (0, CPUCLOCK_SCHED)
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: MAKE_PROCESS_CPUCLOCK (0, CPUCLOCK_SCHED),
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# define SYSDEP_GETTIME_CPUTIME \
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case CLOCK_PROCESS_CPUTIME_ID: \
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case CLOCK_THREAD_CPUTIME_ID: \
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retval = maybe_syscall_gettime_cputime (clock_id, tp); \
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if (retval != EINVAL || !__libc_missing_posix_cpu_timers) \
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__set_errno (retval); \
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retval = hp_timing_gettime (clock_id, tp); \
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# if !HP_TIMING_AVAIL
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# define hp_timing_gettime(clock_id, tp) (__set_errno (EINVAL), -1)
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#include <sys/time.h>
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#include <libc-internal.h>
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#include <ldsodefs.h>
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/* Clock frequency of the processor. We make it a 64-bit variable
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because some jokers are already playing with processors with more
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static hp_timing_t freq;
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/* This function is defined in the thread library. */
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extern int __pthread_clock_gettime (clockid_t clock_id, hp_timing_t freq,
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__attribute__ ((__weak__));
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hp_timing_gettime (clockid_t clock_id, struct timespec *tp)
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if (__builtin_expect (freq == 0, 0))
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/* This can only happen if we haven't initialized the `freq'
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variable yet. Do this now. We don't have to protect this
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code against multiple execution since all of them should
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lead to the same result. */
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freq = __get_clockfreq ();
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if (__builtin_expect (freq == 0, 0))
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/* Something went wrong. */
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if (clock_id != CLOCK_PROCESS_CPUTIME_ID
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&& __pthread_clock_gettime != NULL)
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return __pthread_clock_gettime (clock_id, freq, tp);
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/* Get the current counter. */
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/* Compute the offset since the start time of the process. */
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tsc -= GL(dl_cpuclock_offset);
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/* Compute the seconds. */
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tp->tv_sec = tsc / freq;
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/* And the nanoseconds. This computation should be stable until
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we get machines with about 16GHz frequency. */
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tp->tv_nsec = ((tsc % freq) * UINT64_C (1000000000)) / freq;
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realtime_gettime (struct timespec *tp)
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int retval = gettimeofday (&tv, NULL);
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/* Convert into `timespec'. */
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TIMEVAL_TO_TIMESPEC (&tv, tp);
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librt_hidden_proto (clock_gettime)
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/* Get current value of CLOCK and store it in TP. */
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clock_gettime (clockid_t clock_id, struct timespec *tp)
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#ifndef HANDLED_REALTIME
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#ifdef SYSDEP_GETTIME
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#ifndef HANDLED_REALTIME
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retval = gettimeofday (&tv, NULL);
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TIMEVAL_TO_TIMESPEC (&tv, tp);
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#ifdef SYSDEP_GETTIME_CPU
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if ((clock_id & ((1 << CLOCK_IDFIELD_SIZE) - 1))
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== CLOCK_THREAD_CPUTIME_ID)
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retval = hp_timing_gettime (clock_id, tp);
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__set_errno (EINVAL);
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#if HP_TIMING_AVAIL && !defined HANDLED_CPUTIME
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case CLOCK_PROCESS_CPUTIME_ID:
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retval = hp_timing_gettime (clock_id, tp);
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librt_hidden_def (clock_gettime)